Dungeon Deathtraps

There’s nothing wrong with pit traps, poisoned darts, or scything blades. Yet these staple traps only scratch the surface of the nefarious machinations and deathtraps imagined in fiction and film. The best traps prove to be more than mere hindrances or cheap “save-or-take-damage” annoyances. Whether they’re elaborate puzzles testing their victims’ cunning or multipart murderers forcing their prey to think quickly to escape certain doom, well-crafted traps can produce encounters just as memorable as any narrowly won combat.

Presented herein are a host of new traps ready for use in any campaign. In the descriptions of these traps, elements with specific trap stat blocks are listed in quotation marks, such as with the “pendulous staircase” or “ignited philosopher’s stone.”

Beyond the Basics

Both versatile and lethal, these simple traps expand upon normal traps and can be utilized in any manner of adventure, from wilderness explorations to high-stakes tomb robberies. GMs seeking even greater variety might choose to alter the types of damage their traps deal or customize cosmetic elements to tie their effects more closely to the traps’ surroundings. A poison dart trap that shoots miniature fangs or a summon monster VI trap that conjures dozens of snakes proves much more thematically appropriate to jungle adventures than the generic standbys.

Spring Tile CR 3

Type mechanical; Perception DC 22; DisableDevice DC 20

EFFECTS

Trigger location; Reset manual

Effect tile springs from floor (1 Atk melee +15 CMB against the target’s CMD to bull rush Large or smaller targets straight up). If the bull rush moves the target high enough to strike the ceiling, the target takes 1d6 points of damage. The target takes 1d6 falling damage for every 10 feet bull rushed. The bull rushed target lands in a square adjacent to the spring tile and must make a DC 20 Reflex save to avoid falling prone.

Magnetized Panel CR 4

Type mechanical; Perception DC 22; DisableDevice DC 22

EFFECTS

Trigger location; Reset automatic

Effect 10-ft.-square magnetic plate (1 Atk +16 CMB against the targets’ CMD to disarm all held metal items); multiple targets (all targets in a 10-ft. square). Disarmed items fly to the plate and stick there. Disarmed items can be removed from plate with a DC 20 Strength check.

Caltrop Burst CR 5

Type mechanical; Perception DC 25; DisableDevice DC 20

EFFECTS

Trigger location; Reset none

Effect explosive burst of caltrops (4d6 damage; DC 17 Reflex save for half); multiple targets (all targets in a 15-ft.-radius burst). After the trap is activated, the floor of the affected area is covered in caltrops.

Dragging Hook CR 6

Type mechanical; Perception DC 24; DisableDevice DC 22

EFFECTS

Trigger location; Reset automatic

Effect hooked harpoon on pull cord (Atk +20 ranged, 1d8+6 damage). On subsequent rounds, if the harpoon hits, the trap makes additional attacks with a +20 CMB against the target’s CMD, using the dragcombat maneuver to pull Large or smaller targets toward its originating point. Removing the harpoon or severing the pull cord is a standard action and deals 1d6 damage to the target.

Pulverizers CR 7

Type mechanical; Perception DC 22; DisableDevice DC 20

EFFECTS

The Double Death

A new take on an old trap, the double death is, at its most basic level, a wide pit trap. Yet those who fall prey to the trap not only find themselves victims, but also bait that attracts their companions to an even deadlier doom. This trap is best suited to characters of levels 8 to 10.

The Trap: A two-level pit trap surrounded by tiles that collapse into a slide. After the first pit trap is triggered, the second gives way a moment later, spilling those trapped down to a spiky doom.

How It Works: As creatures near the brazier, the first part of the trap is sprung, with the floor dropping away as soon as 150 pounds of weight enter the squares immediately surrounding the fixture. This functions just as a standard pit trap, dropping victims 15 feet, as described in the “upper pit.” Unseen from the surface, the collapse of the first pit trap sets off a secondary mechanism that requires 2 rounds to activate. At the end of these rounds, the edges of the open pit collapse into steep slides, potentially spilling anyone at the pit’s lip into the pit. At the same time, the floor of the upper pit collapses, spilling its contents another 20 feet into the spear-lined depths. The dropping away of the false floor creates a slight lip that the most agile victims might be able to cling onto to prevent themselves from falling, but such a miraculous save proves difficult at best.

Pendulous Staircase

A sort of double trap, the pendulous staircase menaces those who tread too heavily upon its fragile steps, threatening to crush climbers like a gigantic pendulum, but also leaving them stranded amid whatever dungeon depth they seek to escape.

TheTrap: A huge but loose length of chain supports this stairway. While it is strong enough to support the stairs and considerable additional burdens, the stairs maintain their position by relying upon fragile moorings fastened into the cylindrical well. As passersby tread upon the stairs, they potentially break these moorings, causing the stairs to sway. As the central column becomes less fixed in place, it crashes against the walls, crushing climbers or sending them careening into the depths.

How It Works: This spiral staircase consists of a central pillar in a 90-foot-deep shaft. Stone steps connect the central pillar to the walls of the shaft. These steps fit into shallow slots cut into the wall. Characters who descend the staircase to the bottom discover a gap between the last step and the floor of the lower chamber.

Among these stairs, spaced approximately 15 feet apart, are several steps deliberately designed to break. These false steps appear nearly identical to the solid steps, though a DC 25 Perception check notices the almost imperceptible cracks. A character who steps on a “breakaway stair” risks falling through the broken tread and falling down to the next twist of the spiral staircase.

Once a step had broken away, any contact with the stairs sets the whole central column swinging. Each round, all characters on the steps must make a Reflex save to avoid the “pendulous staircase.” The DC of this Reflex save increases by 1 for every one of the 14 breakaway stairs that is broken. If a character fails her Reflex save, roll 1d20 and add the number of stairs broken, then reference the Pendulous Staircase Effects chart to determine how the stairs’ movement imperils the character.

Table: Pendulous Staircase Effects

The PCs are bounced against the wall, taking 1d6 points of bludgeoning damage.

9–12

A DC 12 Acrobatics check is required to move. More steps become unstable, and 1d4 –2 breakaway stairs snap out of place.

13–16

The PCs are struck by the pillar or slammed against the wall, taking 2d6 points of bludgeoning damage.

17–20

The PCs are thrown from the stairs, taking 1d6 points of damage for every 10 feet fallen.

21–24

The PCs are struck violently by the pillar or smashed against the wall, taking 4d6 points of bludgeoning damage.

25–28

A DC 20 Acrobatics check is required to move. More steps become unstable, and 1d4 breakaway stairs snap out of place.

29–32

The PCs are clobbered by the pillar, taking 8d6 points of bludgeoning damage.

33–34

The stairs collapse. The PCs fall from the stairs, taking 1d6 points of damage for ever 10 feet fallen. In addition, falling debris causes all PCs to take 8d6 points of damage (DC 15 Reflex save for half).

Philosopher’s Stone

Alchemy is the art of turning lead into gold, the base into the sublime, the physical into the spiritual. Also, it is the art of making things explode.

The Trap: A giant metal boulder filled with volatile chemicals careens down a hall, then back again, possibly lodging in the narrow passage. Alcoves line the hall, potentially giving those in the boulder’s path shelter, but interconnected spring systems behind the statues within mean that pushing a sculpture in on one side of the hall pushes those on the other side out, forcing those seeking refuge in the alcoves across the hall into the path of the thundering boulder.

How It Works: Two components make up this trap: a giant metal boulder filled with volatile chemicals (the philosopher’s stone); and twin sets of “tethered statues” lining each side of the hall.

Philosopher’s Stone: The philosopher’s stone reprises the classic runaway boulder trap with an alchemical spin. A 15-by-10-foot pressure plate fills the centermost length of a lengthy corridor. After the trap is set off with an audible click, the philosopher’s stone begins rolling. The PCs have 1 round to react to the boulder rolling down the ramp. After the first round, the jostling of chemicals within the stone causes it to light, propelling the “ignited philosopher’s stone” by its internal explosions like a Catherine wheel firework. Sparks shoot out of the boulder, sending it spinning forward. Creatures that didn’t manage to escape the lower hall in the round before the philosopher’s stone ignites must save versus the “ignited philosopher’s stone.” The stone bowls over any creatures of Medium size or smaller that it strikes and continues moving. Creature of Large size or greater halt the movement of the stone, but take double damage from the trap. Magic that creates solid barriers—like interposing hand or the various wall spells—can halt the stone, though the violent thrust of telekinesis or a ring of the ram merely jars the boulder. A creature can attempt to halt the philosopher’s stone by physical force, but it must make a DC 30 Strength check and is struck by the trap without receiving a saving throw. Those who succeed at this Strength check halt the boulder, while those who fail are bowled over as normal.

The philosopher’s stone has enough momentum to roll down the hall once, ascend halfway up the ramp on the far side of the passage, and—1 round after its initial roll through the hall—barrel back through the passage before coming to a rest not far from the bottom of the ramp it initially hurtled down. After losing its momentum, the stone stops expelling chemical fire but still blocks the hall. Creatures of Medium size or smaller can squeeze past, though the “blocking boulder” is still covered in caustic chemicals and might roll to crush those who try to slip around it. The boulder can be moved with a DC 24 Strength check, though any creature that voluntarily touches it takes 1d6 points of acid damage. It can also be destroyed, though this requires some effort (the thick steel ball has hardness 10 and 1,800 hit points).

Statues: The PCs have 1 round of warning before the philosopher’s stone bowls down the hall, and a second round in which to react before it makes its second pass. Those in the corridor who make a DC 26 Perception check notice that the statues in the hall’s alcoves are on plates with small rollers and have spring mechanisms affixed to their backs. Any creature that makes a DC 20 Strength check can force a statue deeper into its alcove, creating a spot for a Medium or smaller creature to stand that is safe from the philosopher’s stone’s burning rampage. The mechanisms attached to the “tethered statues” are more than mere springs, though. Any creature that pushes a statue deeper into a wall causes all three statues on that side of the hall to slide back, thus opening not one, but three 5-foot-square alcoves on that side of the hall. At the same time, with the same amount of Strength that the creature pushing back a statue exerted, the three statues on the other side of the hall slide out. If two creatures on opposite sides of the hall attempt to push statues into the alcoves in the same round, both must make opposed Strength checks to see who succeeds in pushing back the statues—the victor pushes his way to safe shelter, while the loser is forced into the hall. The shapes of the “tethered statues” are such that they never slide fully into the hallway—or into the path of the philosopher’s stone. If multiple creatures seek shelter by pushing back statues on the same side of the hall, the boulder can pass them by without harm, while those who seek opposing shelters face a startling tug-of-war with a swift and deadly result.

EFFECTS

Tethered Statues

CR 4

Type mechanical; Perception DC 26; DisableDevice DC 26

EFFECTS

Trigger location Reset automatic

Effect Statues can be pressed deeper into their alcoves with a DC 20 Strength check. Pressing a statue deeper into its alcove forces any creatures attempting to do the same on the opposite side to succeed at an opposed Strength check or be forced back into the hall.

Pipes of Doom

Water is the bane of many adventuring parties, typically for the tentacled terrors and coiling serpents found within. But sometimes, water proves deadly enough by itself.

The Trap: Water pressure prevents a rusted iron door from opening while the pool it rests within stands full. Two pillars support the ceiling directly over the water, their foundations composed of highly buoyant material forced into a stationary position at the tops of water-filled pipes beneath the pool’s floor. A valve opposite the door opens drains beneath the room. As the water in the room and the pipes drains out, the speed of the drainage causes the pillars to descend at a rate faster than the water in the pool, potentially trapping and crushing creatures in the pool.

How It Works: A rusted iron door stands at the bottom of a 15-foot-deep pool of water. The door has hardness 10, 120 hit points, and a break DC of 35 due to the water pressure aiding in holding it closed. The added hindrances of moving and attacking underwater make reaching or destroying the door difficult. Fortunately, a valve opposite the door opens drains in the floor, allowing the water to flow out—with deadly side effects.

Those who succeed on a DC 22 Perception check notice the floor of the pool contains a circular pattern of holes at its center, as if it were the subtle opening to a large drain. A DC 28 Perception check also notices very tight gaps around the bases of the twin pillars rising between the pool and ceiling. Any creature that succeeds on a DC 16 Perception check also notices a wheel-shaped valve at the pool’s bottom, and upon reaching it can employ it with a DC 20 Strength check. The valve only works in one direction, opening drains hidden in the pool’s floor, but possessing no ability to close them. Once these drains are open, three pipes begin draining water out of the room: two steadily lowering the water beneath the pillars and one slowly draining the pool itself.

As the pillars are affixed to a buoyant material held aloft by the water in the room, and those pillars in turn support the ceiling, draining the water below them causes the ceiling to begin lowering at a rate of 5 feet per round. The slow drainage of the pool also causes the water level to drop at a rate of 5 feet every 2 rounds. Creatures in the pool thus have 2 rounds to escape the pool before the ceiling reaches a point that it traps them in the pool’s basin, and another 3 rounds after that before the ceiling of the “crushing pool” slams down upon them. The ceiling could potentially be destroyed, but it has hardness 8 and 760 hit points. Creatures trapped beneath the ceiling after it collapses fully take 1d6 points of nonlethal damage every round as if they were buried by a cave-in.

The door is recessed enough that it can be manipulated after the ceiling descends and the water drains out of the room—reducing its Break DC to 25.

Crushing Pool CR 16

Type mechanical; Perception DC 28; DisableDevice DC 28

EFFECTS

Terrible Thurible

Bane of overzealous thieves, this trap grows worse by the moment, though a simple sacrifice at the right moment might save others from choking death and whirling flames. This trap is best suited for characters of levels 6 to 8.

The Trap: Tampering with the chests releases the thurible hanging against the wall, a container filled with black powder and poison. If allowed to swing across the room, it ignites upon coming in contact with the statue’s firepot. The shape of the thurible, the flexible cord, and the exploding powders within the heavy container inside send the thurible reeling around the room, striking those within as it spreads flame and toxic dust.

How It Works: The lids of the chests in this room are connected to mechanisms in the floors and walls connecting to the hanging thurible. Those who investigate the chests can discover a simple switch in either with a DC 26 Perception check, though the device obviously doesn’t connect to anything deadly within the chest. Those who investigate the hanging thurible can make Perception checks at the same DC to detect an equally simple clasping device attaching it to the wall.

Should the chest lids be lifted, the switches are triggered, causing the heavy thurible hanging on the wall to unclasp and swing down. Any creature in the 10 squares directly between the “swinging thurible” and the statue are attacked as noted below. The attack is slow and easy to avoid, but still packs something of a punch. If it strikes a creature in its flight, it deals damage as noted and the impact causes it to stop moving, circumventing the trap’s other dangers.

If no creatures block the way between the thurible and the statue, or if it misses them, the thurible swings to the extent of its cord, pausing over the open flame. This causes the alchemical mixture within the container to erupt violently into flames, turning the metal pendulum into a “lit thurible” that begins spinning about the room. The cord holding the flaming sphere is elastic enough to erratically bounce and swing the thurible with the force of a bludgeon, making any creature in the room a target for its bounding flight. At the same time, the flaming thurible expels doses of deadly ungol dust, exposing everyone in the room.

The thurible has enough explosive powder and ungol dust to be a threat for 3 rounds, after which its swinging slows and it gradually comes to rest at the room’s center. The chests can be investigated in safety at this point; their contents are left to the GM to decide.